Electric switching device



E. THOMSON.

- ELECTRIC SWITCHING- DEVICE. APPLICATION. FILED OCT. II, I917.

Patented Apr. 26,1921.

Inventor- Elihu Thomson,

His Affor'nes; I

. ELIHU THOMSON, OF SWAMP SCOTT, MASSACHUSETTS; AS SIGNOR T0 GENERAL mm.

TBIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC SWITCHING DEVICE.

Specification of Letterslatent. Patent d A 26 192 Application filedOctober 11,1917. Serial No. 196,056.

T 0 all whom z'tmay concern:

Be it known that I, ELIHU citizen of the United States, Swampscott,county of Essex, State of assachusetts, have invented certain new anduseful Improvements in Electric Switching THOMSON, a

Devices, of which the following is a specification.

My invention relates to electric switching means and has for its objectto provide an electric switching device for high potential directcurrents in which the c rcuit is interrupted in a high pressureatmosphere and in a strong magnetic field to produce an exceedinglyeffective are extinguishing aca switch. 10. This tion. A further objectof my invention is to provide a switching device of the magneticblow-out type in which the blow-out means also controls the circuit ofthe switch. The novel features of my inventionwill be definitelyindicated in the claims appended hereto, while the features ofconstruction and mode of operation will be understood from the followingdescription taken in connection with the accompanying drawing, in which:a

Figure its a view, partly in section, of an electric switch of thesingle break type embodying the features of my invention; Figs. 2 and 3are views, partly in section, of electric switches embodying modifiedforms of my invention; Fig. 4.- is a view,

partly in section, of a switchof the double break type embodying thefeatures of my invention; Figs. 5 and 6 show a modification in thelining of-the switch chamber, and

Fig. 7 shows a detailed view of a the switch.

In Fig. 1 theswitch of my invention comprises a vessel or container -1provided with portion of a portion 2, approximately ellipsoidal inconfiguration, formmg an arc extinguishing chamber 3, and a tubularportion 4 forming a compartment in communication with the arcextinguishing chamber. Within the compartment of the tubular portion 4:is

movably disposed or slidabl'y mounted, a

contact member or electrode 5 of magnetic material in whole or partforming the movable contact member of the switch. The contact member 5cooperates with a fixed contact member 6, supported by an integralportion of an insulating lining 7 for the arc extinguishing chamber 3,to control the circuit throu h the switch. The lining 7 residin at is adapted to withstand the heat of the are asthe contacts separate, and is,therefore,

made of heat resisting insulating material and preferably low expansionmaterial such as fused quartz or admixtures of quartz and otherconstituents having similar propert1e s The contact member 5 is biasedto circult closing direction or i-n-engagenient with contact 6 by abiasing means or spring 8.- i

For actuating the movable contact member 5 in switch opening directionandcone trolling the operation of the switch, I provide anelectroresponsive actuating. means or electrical winding 9. energizedfrom any suitable source of power and controlled by electrical winding 9is preferably carried on the tubular portion/l of'the vessel 1 whichisof non-magnetic metal or metal of feeble magnetism and cooperates withthe magnetic or movable contact member 5 to produce a flux therethroughand thereby a strong magnetic field within the arc extinguishing chamber3 at the point of separation of the contact members 5 and 6. The winding9, therefore, cooperates with the contact member 5 not only to controlthe circuit of the switch but also to produce a magnetic blow-out actionon the are formed as the contacts separate. The areextinguishing'chamber 3 ,is also provided with an atmosphere which ismaintained under high pressure through the connection of the vessel 1 toa source, for instance,of compressed air by means of a supply pipe 11suitably insulated and extending through an opening in tubular portion4.

of the vessel. The atmosphere within the chamber maybe of variouspressures or densities' but I prefer, to maintain in the chamber apressure of approximately 1000 pounds to the square inch when potentialsof several thousand volts are to be interrupted.

The circuit termina-ls'of my-switching device comprise terminal member12 which 1s connected to or in conductive relation with the tubularportion 4 of the vessel 1 and the terminal member 13 which is connectedto the stationary or fixed contact member 6 so that the circuit throughthe switching device is from terminal member 12 to the tubular portion 4of vessel 1, thence through the movable contact 'member 5 to fixedcontact 6 and thence to terminal member 13. The electrodes 5 and- 6 arenormally biased to circuit closing position by the spring 8. I

When the circuit through, the switch is to be opened, the control switch10 is closed to energize the electromagnetic means or winding 9, whichthereupon attracts the magnetic member or movable contact 5 and movesit, against the force exerted by spring 8, out of engagement with thefixed electrode 6. The contacts separate in the arc extingulshingchamber 3 and the are formed is blown or attenuated by the magneticfield set up by the winding 9 and contact member 5 in such a manner asto tend to wrap itself about the contacts, or .in other words, is blowninside around the lining 7 of the chamber 3 and so extended that thepoten-' tial of the arc is exhausted in the attempt to maintain an arcin the dense atmosphere and in the strong magnetic field. Due-to thecombined action of the-magnetic field and the pressure of the atmospherewithin with great certainty. The have flutings 5 Fig/7, to allow quickequalizing gas preswith the gas in the in extinguished member 5 maylength, as shown in action in opening by sures back of'member 5 chamber3. t

- In Fig. 2 is shown a switching device in which the tubular portion 4of the vessel 1 is extended and in which the movable contact 5 isbiased'by a spring 14 in circuit opening direction out of engagementwith the fixed contact 6. The control switch 10 is provided with arheostat 15 to vary the current in the electrical winding 9. To closethe circuit through the switching device, the control switch 10 is movedto the contact button 16 cutting out the resistance from the circuit ofthe winding 9 and causing the ,7 winding to be sufficiently energized tomove the movable contact member 5 into engagement with the fixed contact6. To open the circuit through the switching device, the control switch10 is moved to contact 17 for instance, thus reducin the current in thewinding 9 sufficiently to enable the spring 14 to move the contact, 5out of engagement As in Fig. 1, the switch a compressed atmosphere 11and the are formed as with" contact 6. is supplied. with by supply pipethe contacts separate is quickly extinguished 1n the arc extinguishingchamber 3 by the bodying combined actionpf the magnetic field set up bythe winding 9 and the density of-the atmosphere within the -chamber. Thefront part of member 5, or that part extending into chamber3, and

tube of iron, while thelrear part slidable in thetubular portion 4,.is-a solid or masslve 1IOI1 core..

In Fig. 3 is shown a switching device ema further modification of myinven- This switch is provided with pneu- For this purpose tion. maticactuating, means.

- the side of the tubular portion exerted from along its l or thecircuit is left broken,

shown of less diameter,

I provide the movable contact 5 with a piston head 18 and upon each sideof the piston head through suitable insulated openings in 4 of vessel 1,extend air supply pipes 19 and 20 provided with suitable control valves.To control the switching device pneumatically, the pressure the supplypipe 19 is suddenly raised to exert a pressure on movable contact 5 tomove it quickly into circuit closing,

position against the force exerted by the spring 14. To open the switch,the pressure exerted by supply pipe 20 is suddenly raised to exert apressure on the contact member 5 sufficient to cause the contact 5 tomove quickly 1n circuit opening direction assisted by the spring14. Theelcctro-magne-tic .mea-ns may be used in combination with the pneumaticmeans, controlled by its switch 10 and rheostat 15, as described in Fig.2, to assist in maintaining the contact the arc rupturing chamber 3, theare formed 5 in'circuit closing position'and provide the magneticblow-out action. Or the pressure in chamber 3 and pipe 20 may beconstant, and the closing and opening may be governed by-raising orlowering of the air pressure in pipe 19, or the chamber in back ofmember 5, which it supplies, a. portion of member 5 acting as a closefitting piston in tubular portion 4. In this figure, the arcinterruptingswitch is shown connected in series-with an ordinary opencircuiting and closing switch 21 'Which can be opened'at once after theformer has done its work. Infact, the valve or other movementscontrolling the former can be connected to op-" crate this ordinaryswitch and so obviate the necessity for keeping the arc interruptercontacts apart when the switchis left open, as when switch 21 is leftopen. 7

In Fig. 4 I have shown the principles of my invention applied to adouble break switch. In this type of switch a vessel 21 is proyidedhaving two separate are extinguishing chambers an insulating lining 24of fused quartz or similar material which also serves to divide thevessel 21 into Between the two-chambers 22 and 23 and supportedby thepentral portion of-the in-' 221 and 23 formed by gaging portions 26 and27 extending into the chambers 22 and 23 respectively. Cooperating withthe contact engaging portions 26 and 27 of member 25"within chambers' 23and 24, respectively, are movable contacts 28 and 29 movable within thecompartments formed in the tubular portions 30 and 31, respectively, ofvessel 21 and biased by springs 32 and 33, respectively, incircuitclosing directlon. These contacts are controlled as describedrelative to the switch of Fig. 1, by-iel'ectrical windings 34 and 35carried by the tubular portions 30 "a1id 31 respectively. The windings34 and 35 may be controlled in various ways, but I prefer to connect thetwo windings in series andcontrol the circuit of both windin' s by acontrol switch 36 so that both win ings 34 and 35 are simultaneouslyenergized or deenergized. The windings 34 and 35 cooperate as described,with the movable contact members 28 and 29 to produce magnetlc fieldsfor the extinguishment of the arcs formed as the contacts separate. Airsupply pipe 37 connectedto the tubular portion of the vessel 21 providesan atmosphere of high pressure within thearc extinguishing chamber. Inorder to equalize the pressures within the two chambers 22 and 23, thecontact block is provided with openings 38 communicating between the twochambers.

The circuit terminals 39 and 40 for. the switch, are connected to thetubular portions and 31 respectively of the vessel 1.

As shown, the contacts 28 and 29 are biased to engage the portions 26and 27 ofmember 25 to complete. the circuit through the switch. To openthe switch, the control switch 36 is closed and the electromagneticmeans or windings-34 and 35 simultaneousl energized to move bothelectrodes 28 and away from the portions 26 and 27 of mem ber 25,causing arcs to occursimultaneously in each arc extinguishing chamber 22and 23 under a dense atmosphereand subjected to a strong magneticblow-out action.

In Figs. 5 and dis shown a preferred configuration of the lining 7 oflow expansion refractory material. To further elon-,

gate the are on rupture the lining is provided with a number ofprojecting portions 7 -projecting radially inward and forming partialsepta, against which and between which, the arc is thrown by themignetic effect, thus contributing very effectually to theextinguishment thereof.

What ,I claim as new and desire to secure by Letters Patent of theUnited States, is.- 1. In an electric switching .device, relativelymovable cooperating contacts, asub- -stantially closed vessel inclosingsaid. con

tacts and adapted to contain a high pressure atmosphere, and. means forseparating said contacts and producing a strong magnetic field whichaids in attenuating the are formed within the high pressure'atmosphereof said ve'sselto extinguish it with great rapidity.

2. In an electricswitching device, a vessel adapted to contain a denseatmosphere,.

means for providing'a strong magnetic field within said vessel, andcontacts controlled by said means and separable within said vessel toform an are which is attenuated and extinguished b the combined actionof said dense atmosp etc and said magnetic field.

- magnetic eating tubular portion, a

3. In an electric switching device, cooperating fixed and movablecontacts, a vessel inclosing said contactsvcontaining an atmos phere athigh pressure, means controlling the operation of-saidmovable contactand 'co6perat1n therewith to produce -a.. strongmagnetic eld at thepoint of separation of said contacts.- a y '4.'A n electric switchingdevice comprising anelectrical winding, a magnetic member movablein'response to said winding and cooperatin therewith to produce a strongeld, a fixed contact member cooperating with said magnetic member tocontrol the circuit of the switch, anda vessel phere within which: saidmembers are separable.

. 5. In an electric switching device, relatively movable cooperatingcontacts, means for producing. a'magnetic' field at the point ofseparation of said contacts, a vessel sur-- rounding saidcontacts havingan atmosphere at high pressure, and a lining for said vessel oflowexpansion refractory material.

' 6. In an electric switching device, a vessel provided with an arcextinguishing cham ber, electroresponsive means 1 associated therewith,a fixed contact,a movable contact cooperatingwith-said means to controlthe circuit through the switchhand to produce a -"strong magnetic] fieldwit in said chamber,

and means for. mainta-iningthe atmosphere within said chamber at a highpressure. a

' 7 In an electric .switchlngdevice, a fixed contact member, acooperating movable .contact member of magnetic material,-a Vesselinclosing-said contact members and providingan arc extinguishing chamberwithin Which said contact members are separable,

mean'sfor producing a dense atmosphere in said chamber, andelectromagnetic means controlling said movable contact member andcooperating therewith to produce an intense magnetic field at the pointof separa-' tion of said contacts. 7 i 8. In an electric switchingdevice, a vessel supplied with an atmosphere underhigh pressure, a fixedcontact carried by said vessel but insulated' therefromfa cooperatincontact-within said vessel mo'vable 'into an out of engagement with saidfixed contact,

and means for controlling said cooperating contact and producing amagnetic field at contact member of so adapted 'to contain ahighpressure atmosmounted" in said i and cooperating contact, means fchamber a high pre electromagnetic bular portion an movable electrode topro field at' the point-of separat tacts. 10.. In an e tion withiavessel havin a closed crating rable with ing within said chamber, forsaid-vessel supportin tact in conducting terminals connecte and to saidtubul means supplyi atmosphere, an ried by"-said said contacts magneticfield.

11. In an electric swi with a vessel having a closed arc extinguishinging fixed and mova within said chamber, ing a compa 1 tact, means fdirection, elect ing said -conta meansfor mai mosphere 'cluding said fib ducing astron of separation 0 12. In an electric switc with a vesselhaving a po closed arc extinguishing c bular portion havingcommunication with; em for maintaining a high pres within said vessel,,a fi said chamber a coopera ably disposed wit electromagnetic means carare extinguishing chamber therein with said movable or maintainingwithin said ssure atmosphere, and

s mountedon said d cooperatin duce a mag ion of said cong with sai neticIectric switch, the combinaa portion forming arc extinguishing chamber,coopfixed and movable contacts sepa-i in said chamber, an insulatinglina tubular portion. said movableconthereto, circuit (1 to said fixedcontact ar portion -.respectively," d chamber with a dense p delectromagnetic means carportion for causing to be separable in a strongtch, the combination portion forming a chamber, cooperattacts separablea tubular portion havfor said movable conor biasing said contact in onetic means for movte direction,

pressure atin said chamber, and means inrst'mentioned means forprog'magnetic field at the point if 'said contacts.

h, the combination rtion forming a amber and a tutment in 'd chamber,means sure atmosphere t in the opposi ntaining a high tin'g contact movdcompartment, ried by said tubular potr contact to contr and to produceof separation tu- 13. In an e ing into ea bers in each of said chambersI contact mem cooperating with the contact engaging portionsof saidfixed contact, means cooperating with each ofsaidmovable contacts toproduce magnetic fields at the part of separationof said contacts andoperative to con-' trol the actuation of said contacts, and meansforamaintaining a high pressure atmosphere within said vessel.

contact within In witness whereof I have hereunto set :myhand this 9thday of October, 1917.

tion cooperating with said movable ol the movement of the same amagneticfield at'the point of said contacts. lectric switching device,the d combination with a vessel having a, portion forming a closed arcextinguishing chamber, cqoperating fixed and movablecontacts separablewithin said chamber, means for maintaining a high density atmosphereWithin said vessel, and electromagnetic means for actuating said movablecontact and for cooperating therewith to produce a strong magnetic fieldat the point of separation of said contacts.

14. In an electric switching device, the combination with a vesselhaving a portion forming a closed arc extinguishing chamber, cooperatingfixed and movable contacts separable within said chamber, means formaintaining the atmosphere within said vessel at a high pressure, meansnormally bias: ing said movable contactin circuit closing direction, andmeans for moving said movable contact in circuit ,opening direction andproviding a magnetic extinguishing action for the arc'form'ed as saidcontacts separate.

15. An e lectric switching device comprisvessel provided with separatearc eshing chambers, a fixed contact mem d vessel between said cham-ELIIIU THOMSON.

